Ophthalmic compositions for use in the treatment of eyes are known in the art. Such compositions may, for example, contain pharmaceutically active agents and be used for the treatment of specific diseases of the eye. Alternatively, or additionally the compositions may be used as tear replacement solutions.
When the ophthalmic compositions comprise pharmaceutically active agents and/or excipients side effects are sometimes observed upon topical application of the compositions to the eye. Such side effects may be related to the dosage and/or duration of the treatment and/or the potency of the active agent. Moreover, the efficacy of the treatment may be reduced if sufficient (for example, a therapeutically active amount) of active agent cannot penetrate the eye upon treatment. For example, if the composition is not sufficiently viscous upon application to the eye, it may run off the eye before a therapeutically effective amount of active agent has penetrated the surface of the eye. Alternatively and/or additionally the effectiveness of the treatment may be reduced if the concentration of the pharmaceutically active agent is low in the composition so that in order to provide a therapeutically effective amount of the agent to the patient, repeated doses of treatment must be applied. In such cases, the efficacy of the treatment will depend on the end users compliance with a specific treatment regime. This may not be desirable as the end users compliance with such a regime may be less than adequate.